Laboratory Guide for Gastroenteritis Outbreaks. Public Health Laboratories Branch Ontario Agency for Health Protection and Promotion

Transcription

1 Laboratory Guide for Gastroenteritis Outbreaks Public Health Laboratories Branch March 2008

2 Table of Contents 1 INTRODUCTION ROLE OF THE LABORATORY COMMUNICATION CONTACT DIRECTORY OUTBREAK NOTIFICATION REPORT ONTARIO PUBLIC HEALTH LABORATORY TESTING PROTOCOL LEGAL SAMPLES AGENTS ASSOCIATED WITH GASTROENTERITIS OUTBREAKS BACTERIAL AGENTS PARASITIC AGENTS VIRAL AGENTS CHARACTERISTICS OF GASTROENTERITIS OUTBREAKS SPECIMEN COLLECTION GUIDELINES GUIDELINES FOR ESTABLISHING TEST PRIORITIES DURING GASTROENTERITIS OUTBREAKS LABORATORY FLOWCHART FOR OUTBREAK SPECIMEN COLLECTION AND TRANSPORT LABORATORY FLOWCHART FOR GASTROENTERITIS OUTBREAKS TESTING GUIDELINES INSTRUCTIONS FOR FAECES SPECIMEN COLLECTION FOR OUTBREAKS Enteric Outbreak Kit Instructions ENVIRONMENTAL SAMPLE COLLECTION Instructions for Food Sample Collection for Outbreaks 22 5 APPENDICES OUTBREAK NOTIFICATION REPORT (ONR) OPHL GENERAL TEST REQUISITION OPHL MULTIPLE SPECIMEN SUBMISSION FORM (MSSF) FOOD BACTERIOLOGY TEST REQUISITION ENVIRONMENTAL BACTERIOLOGY SWAB TESTS REQUISITION BACTERIOLOGICAL ANALYSIS OF WATER - OFFICIAL AGENCY TEST REQUISITION (MULTIPLE SAMPLE) BACTERIOLOGICAL ANALYSIS OF WATER - OFFICIAL AGENCY REQUISITION (SINGLE SAMPLE) LABSTRACT: LAB-SD-001, DOCUMENTATION CRITERIA FOR ACCEPTANCE OF PATIENT SPECIMENS LABSTRACT: LAB-SD-002, CLOSTRIDIUM DIFFICILE TOXIN TESTING SPECIMEN ACCEPTANCE CRITERIA37 6 CONTRIBUTORS 38 7 INDEX Laboratory Guide for Gastroenteritis Outbreaks - Table of Contents Page 1

3 1 Introduction The (OPHL) consist of a Central Laboratory in Toronto and eleven strategically located Regional Laboratories throughout the province. This Guide provides information regarding the laboratory services available at the for the investigation of a gastroenteritis outbreak, including: The role of the laboratories, contact information, and the diagnostic laboratory tests available Lists of agents associated with, and common causes of, gastroenteritis outbreaks Guidelines for the collection and transportation of specimens. The analytical services available through the system assist in determining the etiology of community and institutional gastroenteritis outbreaks. 1.1 Role of the Laboratory The system provides laboratory services: 1. To advise at the start of an outbreak on the collection and transportation of appropriate specimens. 2. To isolate and identify the etiological agent(s). 3. To assist in determining the reservoir of infection and mode/vehicle of transmission. 4. To provide primary testing of specimens/cultures and co-ordinate the involvement of additional reference laboratories as required. 5. To communicate both positive and negative laboratory results promptly to the local Health Unit/Institution. The success of the laboratory testing depends on the prompt receipt of well chosen and properly collected specimens. When a gastroenteritis outbreak is identified, the laboratory requires timely relevant clinical and epidemiological information so that it can quickly plan strategies, establish priorities and organize its material and personnel resources Laboratory Guide for Gastroenteritis Outbreaks - Introduction Page 2

4 2 Communication Effective communication is a critical factor in the successful investigation of outbreaks. It is important to have simple and direct lines of communication and the information exchange must take place only through designated contact persons at the health unit/institution involved and the laboratory. Please refer to the Contact Directory below for the appropriate contact in outbreak situations. The Public Health Laboratory representative should be involved when an outbreak is identified to provide information regarding the collection and transport of specimens and for reporting of results. 2.1 Contact Directory Most up to date version can be found on the website at Central Public Health Laboratory, Toronto Address: (OPHL) 81 Resources Road Toronto ON M9P 3T1 OPHL HELPLINE (Monday to Friday 8:00 AM 5:00 PM) Tel: AFTER HOURS EMERGENCY RESPONSE LINE Tel: Hours of Operation Monday to Friday 8:00 AM 5:00 PM Location/Position Telephone # Fax # Manager, Direct Services Kits and Supplies Order Desk Medical Microbiologist, Clinical and Environmental Microbiology Office Manager, Clinical and Environmental Microbiology Head, Enteric, Environmental, Molecular Surveillance and STI Head Technologist, Enteric Head Technologist, Environmental Microbiology Head Technologist, Parasitology Laboratory Head Technologist, Molecular Diagnostics Medical Microbiologist, Clinical Virology Manager, Clinical Virology Head Technologist, Virus Detection Laboratory Guide for Gastroenteritis Outbreaks - Communication Page 3

5 Regional Public Health Laboratories Hours of Operation Monday to Friday 8:00 AM 5:00 PM Regional Public Health Laboratories Telephone # Fax # Hamilton 250 Fennell Avenue West, P.O. Box 2100 Hamilton ON L8N 3R Kingston 181 Barrie Street, P.O. Box 240 Kingston ON K7L 4V London St. Joseph s Regional Mental Health Centre th 850 Highbury Avenue, 5 Floor, P.O. Box 5704, Postal Station A London ON N6A 4L Orillia 750 Memorial Avenue, P.O. Box 600 Orillia ON L3V 6K Ottawa 2380 St. Laurent Blvd. Ottawa ON K1G 6C Peterborough 99 Hospital Drive, P.O. Box 265, Peterborough ON K9J 6Y Sault Ste. Marie 160 McDougall Street, P.O. Box 220, Sault Ste. Marie ON P6A 5L Sudbury 1300 Paris Street, Suite 2 Sudbury ON P3E 6H Thunder Bay Timmins 336 South Syndicate Avenue Thunder Bay ON P7E 1E3 67 Wilson Avenue Timmins ON P4N 2S Windsor 3400 Huron Church Road, P.O. Box 1616 Windsor ON N9A 6S Laboratory Guide for Gastroenteritis Outbreaks - Communication Page 4

6 2.2 Outbreak Notification Report The Outbreak Notification Report (ONR) (Appendix) is a critical component of effective communication between the health unit/institution and the laboratory. The following information is required for outbreaks of gastroenteritis and is requested upon initial telephone notification to the laboratory: 1. Outbreak number assigned by the local Health Unit 2. Location of the outbreak (name and address of the institution/facility) 3. Health Unit/Institution Outbreak Coordinator contact information 4. Source or event associated with the outbreak 5. Date of onset 6. Number of persons ill/at risk/hospitalized/deceased 7. Number of residents/patrons/staff 8. Most common symptoms 9. Incubation period, if known 10. Duration of illness 11. Reports of any pathogens isolated by other laboratories, related to same outbreak 12. Suspected mode of transmission 13. Suspect meals and interval between the meal and symptoms 14. Travel or other history, if pertinent 15. Number of stool samples that will be submitted. 16. Number and type of food or environmental samples that will be submitted The OPHL Outbreak Notification Report is available on the OPHL website under the Gastroenteritis Outbreak Guide at The completed form can be faxed or the information may be telephoned to the laboratory contact individual identified at the start of an outbreak Laboratory Guide for Gastroenteritis Outbreaks - Communication Page 5

7 2.3 Ontario Public Health Laboratory Testing Protocol The following protocol is typically followed by the during a gastroenteritis outbreak: 1. An analysis for the detection of the agents listed in Agents Associated with Gastroenteritis Outbreaks (page 7 of this Guide) - is conducted on specimens collected from symptomatic cases. 2. Bacteriology, virology, and/or parasitology examinations are performed simultaneously. 3. Once an agent(s) has (have) been identified, analyses performed on specimens from patients with compatible symptoms are focused on that agent. 4. Where no agent is identified from the first group of symptomatic cases, additional specimens may be tested as determined by the Institutional Outbreak Coordinator and Medical Officer of Health in consultation with the Public Health Laboratory Manager or Medical Microbiologist. 2.4 Legal Samples The laboratory must receive prior notification that a legal sample has been collected and will be submitted. Legal samples must be hand delivered to the Public Health Laboratory to a Senior, Head Technologist or Manager. Once the legal sample is received in the Laboratory, a Chain of Custody form 1 must be signed by the individual delivering the samples and the legal seal verified as intact by both the individuals delivering and receiving the package. 1 If a chain of custody form is not available to the submitter, one can be obtained from the laboratory Laboratory Guide for Gastroenteritis Outbreaks - Communication Page 6

8 3 Agents Associated with Gastroenteritis Outbreaks Listed below are bacterial, parasitic and viral agents associated with diarrhoeal / gastrointestinal disease and for which laboratory investigations are performed for gastroenteritis outbreak related clinical specimens. 3.1 Bacterial Agents Bacillus cereus (food submissions only) Campylobacter species Clostridium botulinum Clostridium difficile (antibiotic-associated/pseudomembranous colitis toxin testing only)* Clostridium perfringens (enterotoxigenic)** Enterohaemorrhagic E. coli O157:H7 (and other verotoxigenic serotypes*) Enteroinvasive E. coli* Enteropathogenic E. coli* Enterotoxigenic E. coli* Enteroadherent E. coli* Salmonella serotypes Shigella species Staphylococcus aureus (enterotoxigenic - food submissions only) Vibrio (V. cholerae, V. parahaemolyticus, V. fluvialis and other species)* Yersinia enterocolytica (pathogenic bio/serotypes) Yersinia pseudotuberculosis *testing only performed upon request **testing only performed when the causative agent is unknown 2008 Laboratory Guide for Gastroenteritis Outbreaks Agents Assoc. w/gastroenteritis Outbreaks Page 7

9 3.2 Parasitic Agents Cryptosporidium species Cyclospora cayetanensis Giardia lamblia 3.3 Viral Agents Adenovirus Astrovirus Caliciviruses (Norwalk-like viruses (Norovirus) and Sapporo-like viruses) Coronavirus Enteroviruses Rotavirus Torovirus Picornaviruses 3.4 Characteristics of Gastroenteritis Outbreaks AGENT EPIDEMIOLOGY INCUBATION SYMPTOMS Bacterial Agents Clostridium difficile (Antibiotic associated / pseudomembranous colitis toxin testing only) Leading cause of nosocomial diarrhea in hospitals and nursing homes Variable Watery diarrhea, fever, loss of appetite, nausea, abdominal pain/tenderness. Bacillus cereus (Food Intoxication) Campylobacter spp. Verotoxigenic E.coli (0157:H7) and other VT types, Enteropathogenic E. coli, Enterotoxigenic E. coli, Enteroinvasive E. coli, Salmonella spp., Shigella spp., Vibrio cholerae and other spp., A well recognized cause of food poisoning Highest incidence is usually during spring and summer months 1 6 hours where vomiting is predominant (toxin); 6 24 hours where diarrhoea is predominant (infection) Varies with the organism; on average, 6 hours to a few days An intoxication characterized in some cases by sudden onset of nausea and vomiting, in others by colic and diarrhea. Gastrointestinal upset, (bloody faeces may be associated with Campylobacter spp. and certain enterotoxigenic E. coli including E. coli O157:H7) 2008 Laboratory Guide for Gastroenteritis Outbreaks Agents Assoc. w/gastroenteritis Outbreaks Page 8

10 AGENT EPIDEMIOLOGY INCUBATION SYMPTOMS Yersinia enterocolytica and other spp. Clostridium botulinum Clostridium perfringens (Food Intoxication) Staphylococcus aureus (Food Intoxication) Parasitic Agents Human botulism is a serious but relatively rare intoxication caused by potent preformed toxins produced by Clostridium botulinum A well recognized cause of food poisoning Preformed toxin Neurological symptoms usually appear within hours. On average, hours On average 2-4 hours Early symptoms and signs are marked by fatigue, weakness and vertigo usually followed by blurred vision, dry mouth and difficulty in swallowing and speaking. Intestinal disorder characterized by sudden onset of colic followed by diarrhea. Nausea is common. Vomiting and fever are usually absent. An intoxication of abrupt and sometimes violent onset, with severe nausea, cramps, vomiting and prostration, often accompanied by diarrhea. Cryptosporidium parvum Worldwide occurrence Not precisely known; thought to be 1 12 days with average of 7 days Cyclospora cayetanensis Giardia lamblia Worldwide occurrence; Ontario outbreaks foodrelated Worldwide occurrence; high prevalence in daycare centres where children are not toilet trained On average, 7 days 3 25 days; median 7 10 days Diarrhoea, abdominal pain; more severe in immunocompromised patients (duration up to 30 days) Watery diarrhoea, anorexia, weight loss, abdominal cramping, flatulence (duration variable up to 4 weeks) Chronic diarrhoea, abdominal cramping, bloating, weight-loss (duration of 2 to 6 weeks) Viral Agents Astrovirus Caliciviruses including Norwalk-like viruses and Sapporo-like viruses Entire year. Mainly infects small children and the elderly Winter, early spring. Most common cause of diarrhoea in adults 1 2 days Diarrhea (duration 1 to 14 days) 1 2 days Diarrhoea, vomiting, fever (duration 24 to 60 hours) 2008 Laboratory Guide for Gastroenteritis Outbreaks Agents Assoc. w/gastroenteritis Outbreaks Page 9

11 Enteric Adenovirus (types 40, 41) Enterovirus Rotavirus AGENT EPIDEMIOLOGY INCUBATION SYMPTOMS Entire year Most common in young children Late summer, fall. Most common in infants and young children Late winter, early spring; infects primarily children; can cause nursing home outbreaks Other viruses including Less well studied. Children Not well established Torovirus, Picobirnaviruses and adults including immunosuppressed patients 5 10 days Watery Diarrhoea, vomiting, fever (duration of 1 7 days) 3 7 days Diarrhoea, rash, low grade fever (duration of up to 14 days) 2 3 days Fever, vomiting, diarrhoea, (duration of 3 9 days) Persistent and acute diarrhea in children 2008 Laboratory Guide for Gastroenteritis Outbreaks Agents Assoc. w/gastroenteritis OutbreaksPage 10

12 4 Specimen Collection Guidelines 4.1 Guidelines for Establishing Test Priorities during Gastroenteritis Outbreaks It is essential to consult the laboratory before changing testing priority. Testing Priority Specimens/Samples 1. Initial specimens from the first symptomatic cases (residents/patrons). 2. Initial specimens from the first symptomatic medical care staff and food handlers. 3. Remnants of suspect meal. 1. Initial specimens from later cases. 2. Initial specimens from asymptomatic dietary staff and food handlers. 3. Water known to have been consumed by symptomatic cases. 4. Top five suspect foods based on Food Specific Attack Rate. 1. Specimens from contacts. 2. Follow-up specimens from all cases Other environmental specimens Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 11

13 4.2 Laboratory Flowchart for Outbreak Specimen Collection and Transport If faeces specimens can be sent same day Food samples collected If faeces specimens or food samples are collected late or on the week- end Refrigerate Store appropriately See Page 21 Refrigerate faeces, See Page 21 for Food Storage Notify Laboratory contact before sending specimens Notify the After Hours Emergency Response Line Send by normal courier Send by normal or arranged courier Note: After hours service is available for receiving STAT specimens 2008 Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 12

14 4.3 Laboratory Flowchart for Gastroenteritis Outbreaks Specimens Collected Outbreak Notification Report (ONR) Laboratory Contact Clinical Specimens (10-15) Environmental Samples Dry Transport Container Enteric Transport Medium SAF Transport Medium Water Food Swabs Enteric Section for Toxin Testing Virology Section Enteric Section Parasitology Section Environmental Microbiology Section 2008 Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 13

15 Disease / Syndrome / Causal Agent / Test Diarrhoea, Antibiotic Associated Clostridium difficile (Pseudomembrane ous colitis) Diarrhoea, Bacterial Routine examination includes Salmonella, Shigella, Campylobacter, Yersinia and E.coli O157:H7 Culture for Vibrio and other food poisoning agents available upon request. Cholera Vibrio cholerae Clostridium perfringens Yersinia Infections Yersinia spp. 4.4 Testing Guidelines Test Code Specimens Collection Kit B03 B02 Faeces 5 10 ml of diarrhoeal faeces Faeces, especially portions containing blood and mucus TB / CD (90 ml sterile container) Faeces collection kit (Cary-Blair or other appropriate transport medium) B02 Faeces Faeces collection kit (Cary-Blair or other appropriate transport medium) S04 Faeces TB / CD (90 ml sterile container) Test Available Bacterial Agents Section TAT Negative Results Reported TAT Positive or Confirmatory Results Reported Notes Toxin detection Enteric 1 day 1 day Refer to Labstract LAB- SD-002 Clostridium difficile Toxin Testing Specimen Acceptance Criteria Culture, identification, serotyping, molecular typing (PFGE) Enteric 3 days Identification of cultures: within 5 days Culture Enteric 3 days Identification of cultures: within 5 days Clostridium perfringens enterotoxin determination Blood, clotted or BL S Agglutination Immunodiagnostics serum Enteric Within 7 days Refrigerate specimen at 4-6 C if transport is delayed. Specimen must be received at the laboratory within 5 days of collection. Consult Medical Microbiologist at or your local Public Health Laboratory. Refrigerate specimen at 4 C if transport delayed. Specimen must be received at the laboratory within 5 days of collection. Within 7 days Freeze specimen for C. perfringens toxin testing at 20 C or lower if not delivered within 1 day of collection. 7 days Within 7 days 2008 Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 14

16 Disease / Syndrome / Causal Agent / Test Cryptosporidiosis Cryptosporidium spp. Cyclosporiasis Cyclospora cayetanensis Giardiasis Giardia lamblia Test Code Specimens Collection Kit P04 P04 P04 Faeces in SAF preservative Faeces in SAF preservative Faeces in SAF preservative 1 part formed faeces to 3 parts SAF Para Para Test Available Parasitic Agents Microscopy for oocysts Microscopy for oocysts Section TAT Negative Results Reported TAT Positive or Confirmatory Results Reported Parasitology 3 days Within 3 days Parasitology 3 days Within 3 days Notes Para Microscopy Parasitology 3 days Within 3 days Collect faeces in clean, dry container. Emulsify faeces in SAF preservative immediately. Submit 1 specimen per day X 3 days. Anti-diarrhoeal medication, radiological dyes (barium) and antibiotics interfere with identification of intestinal protozoa Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 15

17 Disease / Syndrome / Causal Agent / Test Diarrhoea, Viral Including Adenovirus, Astrovirus, Calicivirus (Norwalk-like viruses and Sapporo-like viruses), Coronoavirus, Enteroviruses, Rotavirus, Torovirus Test Code Specimens Collection Kit V40 V06 Faeces Test Available Sterile Electron container microscopy (refrigerate following Direct antigen collection and testing for transport) Rotavirus (Regional Labs only) Faeces Virus TM Virus isolation (Enteroviruses only) Faeces Viral Agents Sterile RT-PCR container (refrigerate (Norovirus only) following collection and transport) Section TAT Negative Results Reported Virus Detection 3 days TAT Positive or Confirmatory Results Reported Within 3 days Virus Detection Preliminary Within 10 days 7 days Virus Detection To be advised To be advised Notes Consult local Public Health Laboratory for outbreak collection kit, in outbreak situations. Collect faeces within 48 hours of onset of illness if possible. Faeces tested by EM from Dec. 15 th to Apr. 14 th Culture and/or EM from April 15 th to Dec. 14 th. Refrigerate specimen if transport is delayed. Consult local Public Health Laboratory for outbreak collection kit, in outbreak situations. Collect faeces within 48 hours of onset of illness if possible. Refrigerate specimen if transport is delayed. Available as research/investigational test. Consult with local PHL prior to sample submission Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 16

18 Disease / Syndrome / Causal Agent / Test Botulism Clostridium botulinum Food-Borne Bacterial Disease (Infection/toxin acquired from food or water) Cryptosporidiosis Cryptosporidium spp. Giardiasis Giardia lamblia Test Code Specimens Collection Kit B02 Remains of meal Original food 200g of food container, if possible. Enclose in Whirl-Pak bag N/A Environmental Commercial swab of food Swab contact surfaces. Test Available Section Food and Environmental Samples Not available at the Call the OPHL. Botulism Reference Centre at or see web site -aspc.gc.ca Food samples are examined for indicators of poor sanitation (HPC, Coliforms, E.coli and total gram negatives) and enteric pathogens including Staphylococcus aureus and Bacillus cereus. Staphylococcus aureus enterotoxin where appropriate. Heterotrophic plate count Enteric pathogens testing available upon request. Environmental TAT Negative Results Reported Culture Within 4 days Environmental HPC: 2 days Enteric pathogens: 4 days TAT Positive or Confirmatory Results Reported Culture within 7 days 2 days Within 7 days Notes Transport food under refrigeration within 2 days. In cases of suspected foodborne illness, contact the local Health Unit. Also see Botulism. Environmental swabs must be refrigerated and transported to the laboratory within 1 day of collection. P01 Water samples Environmental Consult Head, Environmental Microbiology at or your local Public Health Laboratory prior to collection of sample, where water is suspected as the source of contamination Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 17

19 Disease / Syndrome / Causal Agent / Test Water-Borne Bacterial Disease (Infection/toxin acquired from food or water) Zoonotic Bacterial Disease (Infection acquired from handling/petting of animals) Test Code Specimens Collection Kit Test Available N/A Water (potable) Water Bottles Total coliforms, Escherichia coli, and Heterotrophic Plate Count (HPC). Enteric pathogens testing available upon request. N/A Water (non-potable) Animal Faeces Water Bottles Enteric pathogens testing available upon request. Faeces Enteric pathogens collection kit testing available (Cary-Blair or upon request other appropriate Transport Medium) Section TAT Negative Results Reported Environmental HPC: 2 days Total Coliform / E.coli: 1 day Enteric pathogens: 4 days TAT Positive or Confirmatory Results Reported 2 days 1 day Within 7 days Notes Sample containers can be obtained from the local Public Health Laboratory. Potable waters must be kept refrigerated and transported to the laboratory within 2 days of collection. Environmental 4 days Within 7 days Non-potable waters must be refrigerated and transported to the laboratory within 1 day of collection. Enteric 3 days Identification of cultures: within 5 days Consult the Enteric Laboratory at Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 18

20 4.5 Instructions for Faeces Specimen Collection for Outbreaks Bacterial, parasitic and viral agents may produce gastroenteritis and the Enteric Outbreak Kit has been designed for the investigation of these agents simultaneously at the beginning of an outbreak when the causative agent is unknown. The use of this kit should be limited to the first specimens collected from symptomatic persons at the onset of the outbreak. The Enteric Outbreak Kit includes three vials, each with a colour-coded cap (Green-Bacterial examination, Yellow-Parasitology examination, White-Viral and toxin examination) to assist Health Units for submitting multiple samples when the causative agent of the outbreak is unknown. If the outbreak is thought to be only bacterial or viral in nature, all three vials do not need to be collected or submitted to the laboratory. The laboratory requisition should accurately reflect the examinations required Enteric Outbreak Kit Instructions 2008 Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 19

21 2008 Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 20

22 4.6 Environmental Sample Collection 1. The analysis of food and environmental samples must be clearly related to outbreak management. In submitting food and environmental samples, it is important to select only those that are known to be or likely to be involved, on the basis of a good epidemiological rationale. 2. Consult the Environmental Laboratory, either in the Regional Laboratory or the Central Laboratory in Toronto prior to specimen collection and submission of food or environmental samples. As with clinical specimens, one Public Health Inspector should be assigned to supervise sample collection and to communicate with the laboratory. 3. When an outbreak is suspected, the institution should set aside samples, at least 200 grams each, of all food served to the affected individuals within 72 hours of the onset of symptoms (in the index case or most recent cases). 4. Prepare a list of suspect foods in order of probability of association. It has been found that 90% of significant analytical results were associated with the following sample types in descending order of probability. a) Poultry b) Beef and Veal c) Pork and Ham d) Fish and Seafood e) Mixed Salads f) Rice Dishes g) Dairy and Egg Products h) Pastry, Pudding and Pie Fillings i) Ice Cream, Non-Cream Pastries and Canned Goods j) Dried Foods 5. Use a Food Specific Attack Rate table to determine which foods are most likely to be involved in the outbreak. Only foods implicated on epidemiological grounds or on the basis of food specific attack rates should be submitted for analysis immediately. 6. When the etiological agent related to the outbreak is unknown, food samples will receive a complete bacteriological screen Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 21

23 7. When the etiological agent has been identified from related clinical specimens, the foods may be analysed for that agent only. 8. Foods not identified as priority in the Food Specific Attack Rate table may be collected but not initially submitted to the laboratory. These samples should be held under proper storage conditions and sent for testing if initial results do not identify an etiological agent. 9. If required, foods for Hazard Analysis Critical Control Point (HACCP) assessment for the food preparation area should be discussed with the laboratory. Submission of these samples should not interfere with the outbreak investigation. Refer to the Health Inspector s Guide to Environmental Microbiology for more detailed information regarding routine food sample submissions Instructions for Food Sample Collection for Outbreaks Preparation As part of good aseptic technique, the time taken for the physical collection of sample can be minimized by ensuring the following: 1. Ensure all materials required are available. 2. Label sample bags before sample collection. 3. Investigate before sampling to determine a plan of action that will minimize sampling time. 4. Complete requisition(s) before or after, never during, sample collection Collection of Sample(s) 1. Use aseptic technique at all stages of sample collection. 2. Collect samples that are representative of the whole lot of food that was available. Collect samples by combining portions from all areas of the available lot, e.g. portions from the top, bottom and middle of the lot. 3. Where possible, the Inspector should try to mix the lot of food before sampling. 4. When the Inspector has reason to believe a lot is not uniform, and it is probable that different parts of the lot will vary significantly, it is advisable to collect multiple 200 gram samples representing different conditions Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 22

24 5. Meals and foods that contain multiple items may be collected as a single sample. If collected as a single sample, the components should be collected in approximately equal amounts. 6. If an individual component is of greater interest than other components of a meal or mixed food, the Inspector can sample the items individually. 7. Separation of meals or mixed foods must be performed at the sampling stage. The laboratory will not separate components of a sample received in the laboratory Large Lots of Food Most commercially prepared foods are produced in very large lots. If a Health Inspector encounters a lot of food that is larger than 2 kilograms, then take five samples of 200 grams each (often referred to as sub-samples) and submit for analysis Small Quantity Samples Situations may be encountered where there is very little sample left. In food poisoning cases, small samples will be processed by the laboratory, but complete analysis may not be possible. If the submitting Inspector indicates a suspected or confirmed etiological agent, that analysis will be given priority. In the absence of such information, the laboratory will exercise judgment and will perform analyses that will most likely provide useful information Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 23

25 Sample Storage It is preferable to deliver samples to the laboratory as soon as possible after collection. If there is a delay then store samples in a secure location where they cannot be tampered with or confused with other existing food. Store shelf stable foods in a dry location protected from light and extreme temperatures. Temperatures outside 15 C to 25 C may compromise the sample(s). Store frozen foods as close to the temperature at which they were found as possible. Store perishable foods at 2-6 C. Temperatures outside of this range are not suitable Shipping Containers Ship all foods in containers with hard walls and lids that are secured in the closed position. Samples must be made secure inside the shipping container so that there is no mechanical damage to the samples that may cause leakage. Samples from shipping containers with leaking samples will not be processed by the laboratory. Ship perishable foods in insulated containers with sufficient cold packs to maintain a temperature as close to 4 C as possible. If ice is used, contain the ice in a manner that does not allow water contact with the samples. Ship frozen foods to the laboratory in an insulated container with sufficient ice packs to maintain the frozen state. Ship dry foods and other shelf stable foods at ambient temperature in a closed container. Shipping containers used for food samples should be dedicated to food samples and not be used for other types of samples. If multipurpose containers are used, they should be decontaminated between uses with an appropriate disinfectant and used according to the manufacturer s instructions. The shipping container must have the following information displayed on the outside of the container: Example Submitting Organization Unique Identifier Contents Peel Region Health Dept. PR#53 FOOD SAMPLES 2008 Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 24

26 Transit Time Submit samples to the laboratory as soon as possible. The objective is delivery within 48 hours. Routine Surveillance /HACCP samples older than 48 hours will be rejected. Samples collected during food borne disease investigations that are part of the implicated meal will not be rejected after 48 hours. These samples are often the only opportunity to determine the cause of an outbreak. Transit time needs to be considered for interpretive purposes by outbreak coordinator(s) Laboratory Guide for Gastroenteritis Outbreaks Specimen Collection Guidelines Page 25

27 5 Appendices The version number is indicated at the bottom of the document. Check the OPHL website for the most recent version for use. Requisitions are available at your local Public Health Laboratory quoting the warehouse stock numbers below. The most recent versions of the Labstracts can be obtained at: Appendix Warehouse Document Title No. Stock Number 5.1 Outbreak Notification Report (ONR) See Page OPHL General Test Requisition O OPHL Multiple Specimen Submission Form O-5037 (MSSF) 5.4 Food Bacteriology Requisition L Environmental Bacteriology Swab Tests L Bacteriological Analysis of Water - Official L-3172 Agency Requisition (Multiple Sample) 5.7 Bacteriological Analysis of Water Official L-4020 Agency Requisition (Single Sample) 5.8 Labstract: LAB-SD-001, Documentation Criteria for Acceptance of Patient Specimens See internet address above 5.9 Labstract: LAB-SD-002, Clostridium difficile Toxin Testing Specimen Acceptance Criteria 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 26

28 5.1 Outbreak Notification Report (ONR) 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 27

29 5.2 OPHL General Test Requisition 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 28

30 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 29

31 5.3 OPHL Multiple Specimen Submission Form (MSSF) 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 30

32 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 31

33 5.4 Food Bacteriology Test Requisition 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 32

34 5.5 Environmental Bacteriology Swab Tests Requisition 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 33

35 5.6 Bacteriological Analysis of Water - Official Agency Test Requisition (Multiple Sample) 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 34

36 5.7 Bacteriological Analysis of Water - Official Agency Requisition (Single Sample) 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 35

37 5.8 Labstract: LAB-SD-001, Documentation Criteria for Acceptance of Patient Specimens 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 36

38 5.9 Labstract: LAB-SD-002, Clostridium difficile Toxin Testing Specimen Acceptance Criteria 2008 Laboratory Guide for Gastroenteritis Outbreaks - Appendices Page 37

39 6 Contributors Peter Boleszczuk, Head Technologist, Environmental Microbiology Laura Burton, Head Technologist, Virus Detection John Jessop, Manager, Sault Ste. Marie and Timmins Public Health Laboratories Marina Lombos, Head Technologist, Enteric Anne Maki, Head, Enteric, Enviornmental, Molecular Surveillance and STI Billy Yu, Head Technologist, Parasitology Reviewed by: Dr. Frances Jamieson, Medical Microbiologist, Clinical & Environmental Bacteriology Dr. Tony Mazzulli, Medical Microbiologist, Virology, Immunodiagnostics, Prenatal, and Preventable Diseases 2008 Laboratory Guide for Gastroenteritis Outbreaks References, Contributions Page 38

40 7 Index A B C D E F G I Acceptance Criteria, Labstract LAB-SD-002, Clostridium difficile Toxin Testing - Specimen Acceptance of Patient Specimens, Labstract LAB-SD-001, Documentation Criteria for Adenovirus...See Diarrhoea, Viral Agents Associated with Gastroenteritis Outbreaks... 7 Antibiotic associated / pseudomembranous colitis... See Clostridium difficile Appendices Astrovirus...See Diarrhoea, Viral Bacterial Agents... 7 Bacteriological Analysis of Water Official Agency Test Requsition (Multiple Sample) Bacteriological Analysis of Water Official Agency Test Requsition (Single Sample) Botulism Calicivirus...See Diarrhoea, Viral Characteristics of Gastroenteritis Outbreaks... 8 Cholera Clostridium botulinum... See Botulism Clostridium difficile... 8 Clostridium difficile (Pseudomembraneous colitis)...see Diarrhoea, Antibiotic Associated Clostridium difficile Toxin Testing Specimen Acceptance Criteria, Labstract LAB-SD Clostridium perfringens Communication... 3 Contact Directory... 3 Coronoavirus...See Diarrhoea, Viral Criteria for Acceptance of Patient Specimens, Documentation Labstract LAB-SD Cryptosporidiosis... 15, 17 Cryptosporidium spp....see Cryptosporidiosis Cyclospora cayetanensis... See Cyclosporiasis Cyclosporiasis Diarrhoea, Antibiotic Associated Diarrhoea, Bacterial Diarrhoea, Parasitic Diarrhoea, Viral Documentation Criteria for Acceptance of Patient Specimens, Labstract LAB-SD Dysentery (Bacillary)... See Food-Borne Bacterial Disease E. coli... See Food-Borne Bacterial Disease Enteric fever...see Diarrhoea, Bacterial Enteric Outbreak Collection Kit Instructions, Faeces Enteropathogenic E.coli...See Diarrhoea, Bacterial Enteroviruses...See Diarrhoea, Viral Environmental Bacteriology Swab Tests Requisition Environmental Specimen Collection Faeces Enteric Outbreak Collection Kit Instructions Flowchart for Gastroenteritis Outbreaks, Laboratory Flowchart for Outbreak Specimen Collection and Transportation, Laboratory Food Bacteriology Test Requisition Food Sample Collection for Outbreaks, Instructions for Food-Borne Bacterial Disease Gastroenteritis Outbreaks, Characteristics of... 8 Guidelines for Establishing Test Priorities during Gastroenteritis Outbreaks Instructions for Food Sample Collection for Outbreaks Introduction Laboratory Guide for Gastroenteritis Outbreaks - Index Page 39

41 K Kit Instructions Faeces Enteric Outbreak Collection L Laboratory Flowchart for Outbreak Specimen Collection and Transportation Laboratory Flwochart for Gastroenteritis Outbreaks Laboratory Service, Role of the... 2 Labstract LAB-SD-001, Documentation Criteria for Acceptance of Patient Specimens Labstract LAB-SD-002, Clostridium difficile Toxin Testing Specimen Acceptance Criteria Legal Samples... 6 M Multiple Specimen Submission Form (MSSF), OPHL N Norwalk-like viruses...see Diarrhoea, Viral O Ontario Public Health Laboratory Testing Protocol... 6 OPHL General Test Requisition OPHL Multiple Specimen Submission Form (MSSF) Outbreak Notification Report (ONR) Outbreak Notification Report (ONR)... 5 P Parasitic Agents... 8 Paratyphoid Fever...See Diarrhoea, Bacterial Pseudomembraneous colitis...see Diarrhoea, Antibiotic Associated R Regional Public Health Laboratories Directory... 4 Role of the Laboratory Service... 2 Rotavirus...See Diarrhoea, Viral S Salmonella paratyphi, A, B, C...See Diarrhoea, Bacterial Salmonella typhi...see Diarrhoea, Bacterial Salmonellosis...See Diarrhoea, Bacterial Sapporo-like viruses...see Diarrhoea, Viral Shigellosis...See Diarrhoea, Bacterial Specimen Acceptance Criteria, Labstract LAB-SD-002, Clostridium difficile Toxin Testing Specimen Collection Guide Staphylococcus aureus... See Food-Borne Bacterial Disease T Table of Contents... 1 Test Requisition, Environmental Bacteriology Swab Test Requisition, Food Bacteriology Test Requisition, OPHL General Test Requsition (Multiple Sample), Bacteriological Analysis of Water Official Agency Test Requsition (Single Sample), Bacteriological Analysis of Water Official Agency Testing Guidelines Testing Priorities during Gastroenteritis Outbreaks, Guidelines for Establishing Testing Protocol, Ontario Public Health Laboratory... 6 Torovirus...See Diarrhoea, Viral Traveller s Diarrhoea...See Diarrhoea, Bacterial Trichostrongyliasis... See Diarrhoea, Parsitic Trichostrongylus spp.... See Diarrhoea, Parasitic Trichuriasis... See Diarrhoea, Parasitic Trichuris trichiura... See Diarrhoea, Parasitic Trichuris trichura... See Diarrhoea, Parasitic Typhoid fever...see Diarrhoea, Bacterial V Vibrio cholerae... See Cholera Vibrio Infections...See Diarrhoea, Bacterial Vibrio spp... See Food-Borne Bacterial Disease Viral Agents... 8 W Water-Borne Bacterial Disease Laboratory Guide for Gastroenteritis Outbreaks - Index Page 40

42 Whipworm... See Diarrhoea, Parasitic Y Yersinia Infections...14, See Diarrhoea, Bacterial Yersinia spp...see Yersinia Infections Z Zoonotic Bacterial Disease Laboratory Guide for Gastroenteritis Outbreaks - Index Page 41